The platypus bill has a multitude of receptors on it. Initially, researchers thought that the receptors were all mechanoreceptors (i. e. for sensing textures, shapes) because platypus can not smell or detect odors underwater. The scientific community was shocked (pun intended) when it was reported that some of the receptors were actually electroreceptors. Design an experiment to determine if platypus prefer to hunt for prey through mechanoreception or electroreception

Experiment: to put insect preys with different textures (but of the same group, for example, moths) into two conditions: 1-pure water and 2-ion-rich water solution. For this experiment, it is important to highlight that the platypus is a semiaquatic mammal that eats insects that fall into the water. Pure water is a poor conductor of electricity, while water containing charged ions (and also impurities) is a good conductor of electricity. In consequence, if the platypus prefers to hunt through electroreception, it is expected that the ability for hunting will be better in an ion-rich water solution than in pure water. Second, if the platypus prefers to hunt through mechanoreception, it is expected that the ability for hunting will vary depending on the type of texture that exhibits insect preys (in this case, moths).  

Explanation:  

Mechanoreception can be defined as the ability to detect and respond to a stimulus by using sensory cells (neurons) that respond to mechanical pressure and/or distortion, while electroreception is the ability to respond to electrical stimuli, thereby detecting weak electric fields in water. In the experiment above described it is possible to determine the hunting preferences under differential electroreception/mechanoreception conditions. Statistical scores such as p-value can be used to determine the outcome of the experiment.